| Code | Description | Behaviour | Remedy |
| STATE 102 | AC voltage too high | Following careful testing and when the grid conditions are within the permissible range again, the inverter will resume feeding energy into the grid. | Check grid connections: If this STATE code keeps recurring contact your solar power system installer. |
| STATE 103 | AC voltage too low | | |
| STATE 105 | AC frequency too high | | |
| STATE 106 | AC frequency too low | | |
| STATE 107 | AC grid outside the permissible limits | | |
| STATE 108 | Stand alone operation detected | | |
| STATE 112 | RCMU error | | |
| Fronius Primo codes beginning with 3xx | | |
| Code | Description | Behaviour | Remedy |
| STATE 301 | Overcurrent (AC) | Short-term interruption while feeding energy into the grid due to over current in the inverter. | Fault is rectified automatically; if this STATE code is displayed all the time: notify your local Fronius service partner. |
| STATE 302 | Overcurrent (DC) | The inverter resumes with its startup routine. | |
| STATE 303 | Power stage set over temperature | Short term interruption while feeding energy into the grid due to over temperature. | Purge openings for cooling air and heat sink if necessary; fault is rectified automatically; if this STATE code keeps recurring contact your solar power system installer. |
| STATE 304 | Internal temperature too high | The inverter resumes with its startup routine. | |
| STATE 306 | LOW PV OUTPUT | Short term interruption while feeding energy into the grid. | Fault is rectified automatically; if this STATE code occurs when there is sufficient insolation (sunlight) contact your solar power system installer. |
| | Intermediate circuit voltage too low for feeding energy into the grid | The inverter resumes with its startup routine. | IMPORTANT! Due to the low level of insolation (sunlight) early in the morning and in the evening, the STATE codes 306 (LOW PV OUTPUT) and 307 LOW PV VOLTAGE) are displayed routinely at these times of day. These STATE codes do not indicate any kind of fault. |
| STATE 307 | LOW PV VOLTAGE | | |
| | DC input voltage too low for feeding energy into the grid | | |
| STATE 308 | Intermediate circuit overvoltage | Short term interruption while feeding energy into the grid. The inverter resumes with its startup routine. | Fault is rectified automatically; if this STATE code is displayed all the time: notify your local Fronius service partner. |
| STATE 309 | DC input voltage MPPT 1 too high | | |
| STATE 313 | DC input voltage MPPT 2 too high | | |
| Fronius Primo codes beginning with 4xx | | |
| Code | Description | Behaviour | Remedy |
| STATE 401 | No communication with power stage set possible | The inverter will automatically attempt to connect again and, if possible, will resume feeding energy into the grid. | If the STATE code is displayed all the time contact your local Fronius Service Partner |
| STATE 406 | Power stage set temperature sensor faulty | | |
| STATE 407 | Internal temperature sensor faulty | | |
| STATE 408 | DC feeding into the grid detected | | |
| STATE 412 | Fixed voltage mode has been selected instead of MPP voltage mode and the fixed voltage has been set to too low or too high a value | – | If this STATE code persists contact your solar power system installer |
| STATE 415 | Safety cut out via option card or RECERBO has triggered | The inverter is not feeding any energy into the grid. | If the STATE code is displayed all the time contact your local Fronius Service Partner |
| STATE 416 | No communication possible between power stage set and control system | The inverter will automatically attempt to reconnect again and, if possible, will resume feeding energy into the grid. | |
| STATE 417 | Hardware ID problem | | |
| STATE 419 | Unique ID conflict | | |
| STATE 421 | HID range error | | |
| STATE 425 | No communication possible with the power stage set | | |
| STATE 426-428 | Possible hardware fault | | |
| STATE 431 | Software problem | The inverter is not feeding any energy into the grid. | Carry out an AC reset (switch the AC circuit breaker off and on); update the inverter firmware; if this status code is displayed all the time please contact your local Fronius Service Partner. |
| STATE 436 | Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced. | The inverter will automatically attempt to connect again and, if possible, will resume feeding energy into the grid. | Update the inverter firmware; if this status code is displayed all the time please contact your local Fronius Service Partner. |
| STATE 437 | Power stage set problem | | |
| STATE 438 | Functional incompatibility (one or more PC boards in the inverter in the inverter are not compatible with each other, e.g. after a PC board has been replaced) | | |
| STATE 443 | Intermediate circuit voltage too low or asymmetric | The inverter is not feeding any energy into the grid. | If the status code is displayed all the time contact your local Fronius Service Partners. |
| STATE 445 | Invalid limit value settings | The inverter is not feeding any energy into the grid for safety reasons. | Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner. |
| STATE 447 | Insulation fault | | If this status code is displayed all the time: notify a local Fronius Service Partner |
| STATE 448 | Neutral conductor not connected | | |
| STATE 450 | Guard cannot be found | | |
| STATE 452 | Memory error detected | The inverter will automatically attempt to connect again, and if possible, will resume feeding energy into the grid. | If the STATE code is displayed all the time: notify your local Fronius Service Partner. |
